Acid-resistant shellac substitute



= Y Josnrrr a. noun, or monrcmrn, new messy, ASSIGNOR, BY Meansassrenmnnms,

'- -1 I ro CARLETON mums, or non'rcnnn,

. No Drawing.

Patented Dec. 1, 1 925.

p A 1,564,002 STA P NEW JERSEY.

acrn-nnslsranr sHELLAc sunsrrrurn.

. T all whom "it may concern:

l Resistant Shellac Substitutes, of'which the following is aspecification.

' synthetic resinous This invention relates to a method of mak- I ing aresinous compound adapted for use as a shellac substitute and relatesespecially to i sisting variousstrong acids and in particustitu te besolub f lar strong sulphuric acid. I A resin suitable for use in makinga spirit varnish or shellac substitute requires a degree of hardness.such that the varnished surface will not become tacky. and preferably ofsuch a degree of hardness that the surface may be readily sandpapered orrubbed down in accordance with the of the trade. As

1 as a solvent for shellac and as the is accustomed to the odor ofalcohol ractice alcohol is genera lyYused jects to foreign ordors it isdesirable in order tomeet this reqluirement that the shellac sub e inordinaryv denatured alc o-'; It is also desirable to have ares1n whichwill not when V, such solutions.

in solution attack the "tin can or other containers used to package Theodor of the resin must not be objectionable and in particular the iimportant to ride to produce a resin meeting t -color should besufficiently light to not greatly change the color of the wood overwhich it is applied or to materially modify the color of stain when thecomposition is used as a varnish stain.

The f invention comprises not only the resin, as such, but solutionsmade therefrom. In carrying out the invention I treat a 4 phenolicbodywith sulphur chloride to form a resinous compound and in doing this itis carefully body and to proportion the sulphur chlo- 1e requirementsaforesaid. Ordinary phenol reacts with sulphur chloride but does notform resins having the desired solubility, hardness and other propertiescombined. The cresols give better results and I have found metaparacresol to be serviceable forthe present purpose and the one which Ishall herein employ for illustrative pur oses. H The term metaparacresolhas been ong used in the substances capable of re painter? and ob- 1 theother hand resin made with ,weight ofsulphur chloride does concentratedsoul so readily, in fact more select the phenolic usually contains 3 tosolution or the commercial sulphur chlo-' Application filed January 1-2,1922. Serial No. 528,839,

trade as covering mixtures of fmetacresol and paracresol, monly producedin the usual such mixtures being comprocesses of specification. It isunderstood necessary to that it is not go to the expense of separatingthe metacresol from the paracrcsol, in m king the products of thepresent invention.

If metaparacresol is treated with an equal weight of sulphur chloride asoft resin easily soluble in alcohol results. This however is too stickyor tacky for use as a varnish resin. If the same cresol is treated withfor example twice its weight of sulphur chloride a resinous body also isobtained but in this case its solubility in alcohol will be poor. resinmade by using one and one-half times-as much sulphur chloride asmetaparacresol is however quite soluble in alcohol and possesses a highdegree of hardness being rubbing'down process'without gaming or roll ng.Resin of this character also has the remarkable property of resistingstrong or even concentrated sulphuric acid. On

not resist than one and one-third parts by weight of sulphur chloride toone part of cresol are required in order to obtain a resin which will beresistant to oil of vitriol. Above this capable of treatment withsandpaper in the 7 the greater the roportion of sulphur chlorideemployed is c more resistant the resin becomes to strong sulphuric acid.The resin ,made from sulphur chloride one and onehalf the amount ofcresol being sufliciently resistant for all practical purposes and besides having a desirable degree of solubility in denatured alcohol.Resins made with a higher proportion of'sulphur chloride are bestdissolved in mixed solvents such as a mixture of alcoholand benzol.

The sulphur chloride em l d b sulphur chloride which" ordinarycommercial 5% of free sulphur in ride may be chlorinated. to asuflicient de gree to remove the free sulphur as for ex- ?fnple byintroducing 5 to 6% of chlorine. this there is some tendency for alcoholinsoluble products to form.

ioo

1 0s the amount of chlorine greatly exceeds f an; equal brown whichisu'sually objectionable.

reaction to or C. Too high a temf perature or too rotracted contact ofanhydrous hydroch oric acid with" the resin solution at elevatedtemperatures tends to form alcohol insoluble products. Q I

The use of a solvent or diluent has advantages, one being that a moreuniform grade of resin isobtained so that through out the mass of resinthere are not portions which contain a lesser percentage of com binedsulphur which would be attacked by sulphuric acid.

The reaction as soon as the sulphur chloride has been in troduced thereaction is practically complete and the solvent and remaininghydrochloric acid may be expelled. This may be carried out by owingsteam or heate air through the solution. Or the benzol' or toluol may bedi tilled and recovered and air blown throu h serves the desiralilepurpose of eliminating a peculiar odor somewhat resembling iodoform thatis present in the crude resin and is objectionab e in a shellacsubstitute. The treatment with heated air may be at, 125 'to 150 C., thehigher temperatures tending to slightly darken the resin. The heatingand air blowing also tend to harden the resin somewhat. If the airblowing is carried out for a protracted period some insoluble resin mayform especially at higher temperatures. It is therefore best to keep theair blowing temperature under 150 C. and blow the resin only for aperiod sufiicient to eliminate the odor. This treatment also eliminatesthe hydrochloric'acid. It is also possible to treat the resin withammonia gas at the close of the air blowing operation to remove allhydrochloric acid. The latter preferably is completely removed in()ldllillflt the resin may not have a rusting actioniyof metals. Howeverthe'fcomplete removal of acid bringswi it 'a color change, the resinwhich is in rily preared from clean, pure cres igh gra e sulphurchloride being of arstra; or ambercolor. Removal of the acidlcauses'thecolor to change t pl a re addition of a small amount of acid will bringback the color and for this purpose I prei i-r to use phosphoric acidalthough other between the cresol and sul phur chloride takes place veryrapidly and the molten resin which.

out.

, metaparacresol acids such as oxalic acid may sometimes be employed.

. The resin in alcoholic solution when neutral has a peculiaraction ontin cans turnmg the surface black. On the other hand when the alchoholsolution is brought over on the acid side by the addition of a smallamount of phosphoric acid the blackening efiect on the tin surfacedisappears. The blackening action is probably due to reaction with theiron beneath the tinned sur- It is my custom in testing samples ofsolutions wit .respect to their action on tin cans to sandpaper away thetin coverin and ap ply the resin'solution directly to t e bright ironsurface. 'Ithen add phosphoric acid to the solution little by littleuntil I find an:

amount suflicient to prevent the surface from blackening while thecoating of the varnish is drying thereon. In a rough and ready way theaddition of phosphoric acid sufiicient to bring about the colorchange ofthe alcohol solution from brown to light yellow sufiices but for a safemar in it is advisable to use somewhat more t an this amount ofphosphoric acid.

be made up in the ratio 4 or 5 pounds of the resin to the' The solutionmay of say gallon 'when employing denatured. alcohol as a solvent. 4pounds per gallon makes a desirable proportion. Some sulphur generallyis present due to moisture in the materials, to sulphur in the sulphurchloride, and also traces of insoluble resin may form during thereaction. These substances may remain in a colloidall dissolved form inthe alcohol for a time ut on standing they eventually separate andsettle formm a light yellow deposit. Preferably there ore I allow thesolution to stand until the major proportion of sulphur This affords abright clear light-colored solution of the desired alcoholic odorcapable when brushed out on wood or other surfaces of drying readilyforming a hard surface which which when the wood is properly protectedby numerous coats may be flooded. with sulphuric acid without anysubstantial action of the surface or on the wood beneath.

As an illustration one part by weight of was dissolved in an equalvolume of toluol and sulphur chloride in an amount one and one-halftimes the wei ht .of'the cresol was slowly added. After yetc. hassettled may be sandpapered and .drochloric acid had been freely evolvedand the reaction had largely subsided: air was blown through thesolution at a temperature approaching 150 C. for a eriod of aboutone-halfhour which sufiice acid and the toluol. The resin so obtaineddissolved readily in denatured alcohol and a solution was made up in theproportion of about four pounds to the gallon, that is to remove the agallon of the solution contained tour e small nmount of sediment of alightyellow color collected at the bottom. The withdrawn and was clearresin solution was ready'for use.

o t on Witter one withresin u this chsracterwus to luce a fragment infotest tuloe and pour o l of V1l1110l OVeli1h. In; other test tubes llaced fragments of shel lac, Congo resin, anilla resin,- ltauri andll'ontianalt rulober resin to which I likewise added oil of vitriol thesulphuric acid acted almost immediately onjall the resins, with theexception ol the synthetic resin, turn-- ing these natural l'QSlIlS.lolaclt and'd1ssolv-' ing and destroyinpthem. Atterdays of exposure tothe oi' ol vitriol my synthetic resin was in no way affected by thestrong acid.

Such solutions therefore may be applied to wood just as shellac is usedand have a useful function in protecting wood from acid 'lunies infactories and elsewhere where the atmosphere is polluted with acidbodies. Various stains or coloring" matters may be added to a solutionprepared as above and till in order to make the solution resemble thecolor or orange shellac, when such an ad'eot is desired, a suitebleorange dve such as chrysoidine may he added in small quantity.

While I have given very specific directions tor preparing the acidresistant shellac suhstituteit should he understood that l do not limitmyself to these cractproportions or procedures vents employed asvariations may he made deviating to a greater orless entent 'lrom thetoregoingprocedure. v The foregoing" is the result of enperirnents whichI have carried out overs long period or" time involving thepreparationot muny hundred samples of resin from phenol or cresol andsulphur chloride and involves thousands oil experiments and l believethat truth these investigations l have set forth one oi the mostdesirable methods 'ducin iheno ic loody with sulphur chloride to prouc-ea product adopted tor nseas a spirit varnis a i What lclaim is? l. Theprocess oil ll'ltl-lfilllfi, a spirit varnish which comprises tinsel-insmetapareeresol with about one and one-half times its weiuht of sulphurchloride the pronouns or u hydrocarbon diluent vvherelov o resin isformed in solution, lolowing; the solution of prowith heuted air at atemperature below 150 The soluing the solution with orto the precise sola sulphur resin hy'treatment ot u whereby the diluent and hydrochloricdissolving the deodorised suflicient to change the solutionv from abrown to a yellow color.

2. The

product in an alcoholic solvent and process ofmaking a spirit varnishwhich. comprises treating cresol with about 1 7 oneand one-hilt timemonochloride ink: the presence of toluol whereby a resinfis formed insolution, hlowheated air wherehy the diluent and hydrochloric acid areremoved dissolving theresinous product an alcoholic solvent and adding asmall encounter an -acid.'sullicient to change the solution from a brownto a yellow color,

s its weight o:t sulphur obtained in so i such acid being less stronglyreactive toward iron and tin, then ishydrochloric acid.

I 3'. The process of making a spirit varnish which comprises treating'meteparecresol with about one and one-half times its weight of sulphurmonochloride in the presence of at least an equal volume of toluolwherchv a resin is formed in solution, blowing the solution with heatedair vvhereht the diluent and hydrochloric acid are removed. dissolvingthe resinous product obtained in an alcoholic solvent and adding a smallamount of phosphoric acid sufficient to change theselution from a browntoe yellow color and to overcome solution.

\ The processol making a spirit varnish which comprises treetingmetaparacresol with more than its weight of sulphur chlo ride whereby aresin is formed in solution blowing the solution With heated air at atemperature below 150 luent and hydrochloric acid are removed,dissolving" the resinous product obtained in on alcoholic solvent andadding; a small amount cl phosphoric acid scient to change the solutionfrom a brown to a yellowcolorh x 5. it varnish resin comprising; hardairhlackening of tin cans hv the G. whereby the dilllli llll blown,deodorized phenolic sulphur chloride 1 resin. and phosphoric acid,

6. A varnish rosin com rising hard blown cresol sulphur chloidde resinend phosphoric acid. i

A varnish "blown, deodorized cresol sulphur chloride resin and an acid,less ective'on iron'end tin than hydrochloric. d. A varnish rosin rideresin of acid reaction. 1 a c 9. Avarnishcomprisinghard, uirhlowmdeodorized phenolic sulphur chloride resin, phosphoric acid and analcoholic solvent.

10. A varnish comprising hard. deodor-' ized cresol sulphur chlorideresin, phosphorie acid and an alcoholic solvent.

ll. A varnishcomprising hard, air-hlown n comprising hol-soluhledeodorized cresol sulphur chle Y resin comprising hard. nitlQli v 1 ingaction upon tin plate.

.' .5 j I v 1,564,002

cresol sulphur chloride resin, phosphoric holic solution of which isfree from lackenacid and'e solvent.- ing action on bright iron. ,-c v12. A spirit varnish comprising hard, de- '15, A sulfur-containing resinthe alcoholicj' odorized cresol Sulphur chloride resin, phossolution otwhich does not blacken brighgg 5 phoric acid and denatured'alcoho'l inthe proiron. I I I portions of about four pounds of resin to the 16. Aphenol sulfur 'chlorid resin, in if :-s gallon of solution. Y solventcomprising alcohol, which solution is 13. A phenol sulfurchlorid resinfihe a-lcofree from blackening: action upontin plate,

holic solution'of which is free from'hlucken and bright iron 14. s Aphenol sulfur chloriii resin alcoif p

